search – Automatically applying filters

I’m looking for some guidance regarding automatically applying filters on behalf of the user. The project I’m working on is a simple graduate job search website. The search results page is very simple, which allows a user to enter a keyword and a location. Currently, there are only 3 filters (Full-time, Part-time, Flexi).

Behaviour 1) If a user enters a keyword, such as Part-time Accountant, and runs a search, the Part-time filter is not automatically enabled.

Behaviour 2) If a user runs a search for Developer, then actively applies the Part-time filter, this filter will remain selected for every subsquent search. So, if the user changes the keyword from Developer to Chef, the Part-time filter will remain checked.

I want to test automatically setting the Part-time filer if a user enters a keyword such as Part-time Accountant, but I’m not sure what should happen to that filter if the user then changes their keyword.

Example:

  1. User runs a search for Part-time cleaner: The system automatically enables the Part-time filter.
  2. User then changes their keyword to Cleaner

In this case, should the system automatically uncheck the filter, as it was the system that checked the filter, not the user? However, doing this would break the exisiting behaviour outlined above (Behaviour 2). My concern is that if the system automatically checks that filter, the user might not realise, so on subsequent searches that filter would always be applied, which could lead the system to serve irrelevant results to the user.